1. Field of the Invention
The present invention relates to a pedal effort reducing apparatus of a clutch pedal for vehicles, and more particularly, to a pedal effort adjusting apparatus for vehicles capable of being used even in high horse power vehicles having a high engine output while reducing a pedal effort which a driver feels during a pedal operation.
2. Description of Related Art
Generally, a passive transmission vehicle includes a clutch which is disposed between a flywheel and an input shaft of a transmission to control engine power delivered to a transmission as needed, in which the clutch has a structure which is operated by a clutch pedal.
A driver frequently operates the clutch pedal as well as an accelerator pedal and a brake pedal while a vehicle is driven. In particular, the driver continuously applies a pedal effort due to the operation of the clutch pedal while driving a long distance, and may feel tired.
To supplement this problem, a clutch pedal apparatus using a turnover spring has been developed. As illustrated in FIG. 1, FIG. 2A and FIG. 2B, the turnover spring 1 includes two coil parts 1a wound in a coil shape, both ends of the turnover spring 1 are coupled with spring bushes 2, the spring bushes 2 penetrate through both side portions of the pedal member 3, respectively, a middle portion between the two coil parts 1a is fitted in a locking groove 4a of a spring bracket 4, and thus the turnover spring 1 is rotatably installed with respect to the pedal member 3.
Here, the spring bracket 4 is integrally coupled with a hinge shaft bush 5, in which the hinge shaft bush 5 is integrally coupled with the pedal 6 while penetrating through an upper end of the pedal 6 and the hinge shaft 7 is fastened with the pedal member 3 after penetrating through the hinge shaft bush 5.
By this configuration, when the pedal 6 rotates (from a dotted line toward a solid line) based on the hinge shaft 7 as illustrated in FIG. 3 by an operation of a driver's foot, the turnover spring 1 is compressed. In this case, a compressive force is delivered to the pedal 6 and thus a reaction force is generated in the pedal 6 in an opposite direction of a load applied to the pedal 6. As a result, the load applied to the pedal 6 by the driver, that is, the pedal effort is gradually increased. In this case, the driver recognizes the reaction force delivered from the pedal 6 to check an operation state of the pedal 6.
Further, the reaction force of the turnover spring 1 is suddenly reduced at the moment that the turnover spring 1 is changed from a dotted line toward a solid line by the continued rotation of the pedal 6 as illustrated in FIG. 3 and the pedal effort of the driver applied to the pedal 6 is also reduced correspondingly, such that the driver has the reduced fatigue feeling due to the reduced pedal effort at the time of the operation of the pedal 6.
However, the structure to reduce the pedal effort of the clutch pedal using the turnover spring 1 as described above is used in the high horse power vehicle having the high engine output, and thus the damage of parts may often occur.
That is, when a clutch disc and the flywheel are connected to each other to deliver power, a sliding phenomenon need not occur between the clutch disc and the flywheel to be able to smoothly deliver the engine power.
Therefore, in the case of the high horse power vehicle having the high engine output, a spring force of a diaphragm needs to be higher than before to prevent the sliding phenomenon from occurring between the clutch disc and the flywheel. To this purpose, the existing structure using the turnover spring 1 has used a method for increasing a diameter of the turnover spring 1 to increase the spring force of the diaphragm.
However, when the diameter of the turnover spring 1 is increased, the load is concentrated on the spring bush 2 which connects the turnover spring 1 to the pedal member 3. As a result, the spring bush 2 may be often damaged and as the diameter of the turnover spring 1 is increased, an initial pedal effort is increased and thus the fatigue of the driver is increased.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.